Inoperable Pulmonary Carcinoid Tumors: Local Control Rates With Stereotactic Body Radiotherapy/Hypofractionated RT With Image-Guided Radiotherapy

Introduction: Surgery is the standard of care for pulmonary carcinoid tumors; however, options for inoperable patients are few. We report the outcomes of inoperable pulmonary carcinoid patients treated with stereotactic body radiotherapy (SBRT).

Patients and methods: From an institutional database, we retrospectively identified patients treated with SBRT for pulmonary carcinoid tumors from 2007 to 2017. Additional inclusion criteria were previous histopathologic diagnosis, age older than 18 years and Karnofsky performance status ≥ 70.

Results: Ten patients were treated for 12 pulmonary carcinoid lesions with 5 to 10 fractions of SBRT. Their median age was 66.5 years (range, 40-83 years) and most presented with nonspecific symptoms of cough, shortness of breath, or hemoptysis. Pathology revealed typical carcinoid for 9 patients, with the 10th with atypical histology. The median prescription dose for all patients was 50 Gy in 5 to 10 fractions (range, 40-60 Gy) with SBRT/hypofractionated radiation with daily image-guided radiotherapy (IGRT) delivered using a linear accelerator with respiratory monitoring. Four patients received 10-fraction hypofractionated radiation with daily IGRT and 6 others received 5-fraction SBRT. The follow-up after SBRT/hypofractionated IGRT ranged from 6 to 56 months (median, 25 months). Four patients were alive with stable disease at their last follow-up. Two patients died from disease progression in the mediastinal lymph nodes as well as in the lung. Both opted for palliative treatment. The other 4 patients died from their comorbid medical conditions, but had stable disease at their last follow-up. Median overall survival was 27.1 months (range, 5.5-56 months).

Conclusion: Pulmonary carcinoid tumors treated with SBRT have a promising tumor control rate and survival.